Sqoop running on only one mapper while using free form query, getting errors when trying to give more mappers by -m

We don't have primary key on oracle table, so we are not mentioning split by command and in mappers i'm unable to give more than 1 mapper. I tried to install Oraoop(Quest connector) , where we don't need to mention Split by command. Even with Quest connector I'm unable to specify more than One mapper, which is causing too much time for import.